3B55.10 Speaker Beats and Interference
Interference and diffraction of sound
A function generator drives two stationary speakers placed in front of the class. The students cover one ear and slowly move their heads around to hear the interference pattern.
-  Function generator
-  Speaker
- Turn on the function generator.
- Set the amplitude to a minimum.
- Set the function generator to produce a 300 Hz sine wave.
- Place the two speakers about 2m apart.
- Connect a function generator to both speakers.
- Slowly increase the amplitude.
- In large classrooms, the approximate distance the students' head must move to go from high amplitude to low amplitude is longer.
- Instruct the students to plug one ear and move their heads from side to side.
- Have the students approximate the distance between region of high amplitude and low amplitude.
- PIRA 3B55.10
- Don't attempt this at home!
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.